Rear sight for machine guns



Dec. 19 1933.

W. C. L. HAUBROE REAR SIGHT FOR MACHINE GUNS Filed July 31, 1931 2Sheets-Sheet 1 "WOR YS 33 GEQMETWOAL. msTr-wMEN 1933' ROE 1,940,416

REAR SIGHT FOR MACHINE GUNS Filed July 31, 1931 2 Sheets-Sheet 2 3 Ti 9L METRIOA... lNSTF-ZUMENTS.

Patented Dec. 19, 1933 UNITED STATES @FFHUZ Werner Christian LassenHaubroe, Copenhagen, Denmark Application July 31, 1931, Serial No.554,235, and in Denmark August 29, 1930 4 Claims.

The invention relates to a sight device for machine guns or the like forfiring against aircraft or the like.

The sight device consists of a front sight and a rear sight member whichlatter is formed as a wire cross supported in a circular ring, the pointof intersection of the wires of the said cross forming the rear sightwhile during the sighting the ring always occupies a horizontalposition. The ring is supported by a lateral arm connected to arotatable rod disposed in a circular casing, thesaidrod being caused bymeans of a pendulum to-remairilq Stantly in vertical positionmduring thesighting, and being adjustable as to length/"so "that the level of thering relatively to the axis of the casing and, thereby,

. to the bore of th@,,.gun-cah be adjusted'fThe vertical adjiistiiientof the ring i's efiected in that a roll disposed on a pin on the rodengages a curve-shaped slot in an adjusting disc in rigid connectionwith a rotatable handle which is fitted with a pointer pointing on ascale the divisions of which correspond to the various heights offlight, in such a manner that the pin with the roll, when the adjustingdisc is moved by rotation of the handle, is shifted either upward ordownward in the casing and, thereby, either lengthens or shortens therod supporting the ring.

On the drawings Fig. 1 shows diagrammatically the sight device accordingto the invention applied to a machine gun,

Fig. 2 diagrammatically the use of the sight devices during sighting,

Fig. 3 the casing of the rear sight device viewed from the side facingaway from the gun.

Fig. 4 a vertical section of the same taken approximately on the lineIVIV of Fig. 6,

Figs. 4a, 4b and 4c are transverse sectional views taken respectively onthe line Iva-Iva, IVbIVb and IVcIVc of Fig. 4,

Fig. 5 the same in front elevation, and

Fig. 6 a vertical cross-section of the same, taken approximately on theline VIVI of Fi 4.

1 is the front sight supported by a clip 2 attached to the machine gun3. The rear sight device is similarly supported by a clip 4 attached tothe machine gun, in such a manner that there will be a certain definitedistance between the two sight devices.

The rear sight device consists of a circular ring 5, Figs. 2 and 5, inwhich a wire cross 6 is stretched out, the point of intersection of thewires of the cross forming the rear sight, while the extreme top of theother sight forms the front sight. The ring 5 is supported by an arm '7connected to a rod 8, which is adapted to rotate in a circular casing 9about a pin 10 attached therein, Fig. 6. The casing 9 is firmlyconnected to the clip 4 and occupies a position alongside the gun andparallel to the vertical central plane of the same, in such a mannerthat the arm 7 supporting the ring 5 projects over the gun. The rod 8consists of two telescoping parts 8 and 8a, the part 8 supporting alateral tap l2 fitted with a roller 11, and the part 8a a pendulum 13,which during the sighting operation tends to cause the rod 8, 8a tooccupy always a vertical position in the casing 9. The pendulum 13 isadapted to be shifted along the rod member 8a, in such a manner thatwhen the sight device is not attached to the gun the said pendulum canbe moved into the casing 9. The clip 4 is rotatably connected to thecasing 9, in such a manner that it can be swung up against the latter,and the supporting arm 7 of the ring 5 is detachably connected to therod 8, in such a manner that the ring and the supporting arm can beseparated from the casing. The parts of the rear sight will thereforeonly occupy little space when not attached to the gun. The roll 11engages a curve-shaped slot 14, Fig. 4, in a guide disc 15 attached tothe end of a pin 16, which is journaledin the wall of the casing 9facing away from the gun and, beyond this wall, supports a handle 17fitted with a pointer 18, Fig. 3, which points on a scale 19 on the wallof the casing. The divisions of this scale correspond to various heightsof flight. The handle 17 is connected to the pin 16 but is free to slidealong the axis of the same and is actuated by a helical spring 20, whichtends to maintain a check-tooth 21, on the side of the handle facing thecasing, in engagement with a toothed ring 22 provided on the Wall of thecasing, the distance between the tooth intervals on the said ringcorresponding to the distance between the divisions on the scale 19.

The sighting device is used in the following manner.

After the height of flight for the aircraft to be fired at has beenmeasured or estimated the pointer 18 of the handle 17 is adjusted to thedivision on the scale 19 corresponding to the measured or estimatedheight of flight. The gun is then directed towards the aircraft, thegunner sighting along the point of intersection of the wire cross 6 andthe point of the front sight 1. The gun has now acquired the elevationcorresponding to the height of flight of the aircraft, see Fig. 1. Afterthe gunner has thus adjusted the elevation of the gun he maintains theline of sight some suitable distance in front of the aircraft, in such amanner that the latter will be directed towards the centre of the wirecross, and when he then sees the aircraft becoming visible inside of thering 5, see Fig. 2, he begins to fire. The trajectory of the projectileswill then be situated in such a manner that the flying machine whilemoving forward must necessarily pass through the said trajectory and,therefore, cannot avoid being hit by one or more of the projectilesfired in succession.

Having thus described my invention, what I claim is:--

1. In a rear sight for machine guns, a casing supported on the rear ofthe gun barrel, a rod composed of two portions one pivotally mounted insaid casing, a pendulum carried by the pivotal portion of said rod andadapted tomaintain the rod in a vertical position, the other portion ofsaid rod being longitudinally adjustable on the first portion tocorrespond to the height of the target, and an annular member supportedon said second portion and carrying a pair of crossed wires theintersection of which constitutes the rear gun sight.

2. In a rear sight for machine guns, a casing supported on the rear ofthe gun barrel, a telescoping rod carried by said casing, one of thetelescoping portions of said rod being pivotally supported, a pendulumcarried by said pivotally supported portion, a disk supported in saidcasing and provided with a curved guide slot, a

roller disposed laterally on the other telescopic portion of the rod inengagement with said guide slot, an operating handle rigidly secured tosaid disk and carrying a pointer, the wall of said casing being providedwith a scale cooperating with pointer to indicate adjustmentscorresponding to the height of the target, and an annular membersupported on said rod and carrying a pair of crossed wires theintersection of which constitutes the rear gun sight.

3. In a rear sight for machine guns, a casing supported on the rear ofthe gun barrel, a rod composed of two portions one pivotally mounted insaid casing, a pendulum carried by the pivotal portion of said rod andadapted to maintain the rod in a vertical position, the other portion ofsaid rod being longitudinally adjustable on the first portion tocorrespond to the height of the target, and an annular member supportedon said second portion and carrying a pair of crossed wires theintersection of which constitutes the rear gun sight, said pendulumbeing slidable on said rod into and out of said casing.

4. In a rear sight for machine guns, a casing supported on the rear ofthe gun barrel, a rod composed of two portions one pivotally mounted insaid casing, a pendulum carried by the pivotal portion of said rod andadapted to maintain the rod in a vertical position, the other portion ofsaid rod being longitudinally adjustable on the first portion tocorrespond to the height of the target, and an annular member detachablysupported on said second portion and carrying a pair of crossed wiresthe intersection of which constitutes the rear gun sight.

WERNER CHRISTIAN LASSEN HAUBROE.

